College of Life Sciences, China Jiliang University, Xueyuan Road 258, Hangzhou 310018, China.
College of Life Sciences, China Jiliang University, Xueyuan Road 258, Hangzhou 310018, China.
Plant Physiol Biochem. 2015 Nov;96:261-9. doi: 10.1016/j.plaphy.2015.08.001. Epub 2015 Aug 6.
Cadmium (Cd) is a major heavy metal pollutant which is highly toxic to plants and animals. The accumulation of Cd in rice grains is a major agricultural problem in regions with Cd pollution. A hydroponics experiment using low grain-Cd-accumulating rice (xiushui 11) and high grain-Cd-accumulating rice (xiushui 110) was carried out to characterize the different responses of rice cultivars to Cd stress. We found that xiushui 11 was more tolerant to Cd than xiushui 110, and xiushui 11 suffered less oxidative damage. Cell walls played an important role in limiting the amount of Cd that entered the protoplast, especially in xiushui 11. Cd stored in organelles as soluble fractions, leading to greater physiological stress of Cd detoxification. We found that Cd can disturb the ion homeostasis in rice roots because Cd(2+) and Ca(2+) may have a similar uptake route. Xiushui 11 had a faster root-to-shoot transport of Cd, and the expression level of OsPCR1 gene which was predicted related with Cd accumulation in rice was consist with the Cd transport of root-to-shoot in rice and maintain the greater Cd tolerance of xiushui 11. These results suggest there are different Cd detoxification and accumulation mechanisms in rice cultivars.
镉（Cd）是一种主要的重金属污染物，对动植物具有高度毒性。在镉污染地区，水稻籽粒中镉的积累是一个主要的农业问题。本研究采用水培实验，以低籽粒镉积累水稻（秀水 11）和高籽粒镉积累水稻（秀水 110）为材料，研究了不同水稻品种对镉胁迫的响应差异。结果表明，与秀水 110 相比，秀水 11 对镉具有更强的耐受性，且氧化损伤更小。细胞壁在限制进入原生质体的镉量方面起着重要作用，特别是在秀水 11 中。镉以可溶部分的形式储存在细胞器中，导致更大的镉解毒生理胁迫。我们发现，镉可能会扰乱水稻根系中的离子稳态，因为 Cd(2+)和 Ca(2+)可能具有相似的吸收途径。秀水 11 具有更快的根到地上部的 Cd 转运，并且预测与水稻中 Cd 积累相关的 OsPCR1 基因的表达水平与水稻根到地上部的 Cd 转运一致，并维持了秀水 11 更大的 Cd 耐受性。这些结果表明，水稻品种中存在不同的镉解毒和积累机制。
